diff --git a/src/mainboard/sifive/hifive-unmatched/Makefile.inc b/src/mainboard/sifive/hifive-unmatched/Makefile.mk
similarity index 100%
rename from src/mainboard/sifive/hifive-unmatched/Makefile.inc
rename to src/mainboard/sifive/hifive-unmatched/Makefile.mk
diff --git a/src/soc/sifive/fu740/Makefile.inc b/src/soc/sifive/fu740/Makefile.mk
similarity index 100%
rename from src/soc/sifive/fu740/Makefile.inc
rename to src/soc/sifive/fu740/Makefile.mk